What does clearing to mineral soil entail?

• A. Removing leaves and twigs only.
• B. Removing fuels until soil beneath is exposed and uncontaminated by organic material.
• C. Raking to collect surface debris.
• D. Clearing all the way down to bedrock.

Answer: (B)

Clearing to mineral soil means removing fuels until the soil beneath is exposed and uncontaminated by organic material. The goal is to reveal a surface of mineral soil by stripping away the organic layer (duff, litter, debris) and any fuels that could carry fire. With the organic layer removed, there’s less fuel continuity and heat transfer, reducing the chance of re-ignition along a fireline. Simply removing leaves and twigs or collecting surface debris leaves some organic material and thus ongoing fuel near the soil surface. Going all the way down to bedrock is unnecessary for typical line construction and isn’t practical on most sites. The essential idea is to expose clean mineral soil so no organic material can sustain the fire at the surface.